1. Field of the Invention
The present invention relates to an electronic control system of a power train for a hybrid electric vehicle. More specifically, the present invention relates to the electronic control system of a power train including three motor-generators.
According to one aspect of the invention, the power train includes a gas turbine and a flywheel, both of which contain motor-generators, and an electric traction motor-generator. According to another aspect of the invention, the present invention includes the logic and power electronics and the associated software with which to control the three motor-generators during all operating modes, i e., during the starting, accelerating, cruising, braking, hill climbing and hill descending modes of operations of the motor vehicle.
2. Description of Related Art
Numerous references describe methods of controlling hybrid vehicles powered by various combinations of heat engines and electrochemical batteries. For example, U.S. Pat. No. 4,042,056 discloses a system whereby an installed battery can be recharged by either house current or a mobile generator. U.S. Pat. No. 4,187,436 describes a solution to the difficult problem of management of the charge of the batteries and U.S. Pat. No. 4,211,930 discloses use of the traction motor in connection with regenerative braking.
U.S. Pat. No. 4,313,080 provides extensive disclosure regarding the management and use of nickel cadmium batteries in vehicle applications and U.S. Pat. No. 4,407,132 describes a synergistic combination of an engine driven generator and a battery for improving the fuel efficiency of the vehicle. More recently, U.S. Pat. No. 4,547,678 discloses the use of a signal processor in the control of the motor generator of a hybrid electric vehicle while U.S. Pat. No. 4,951,769 describes the use of inverters and rectifiers in hybrid electric vehicles. In a variation on conventional hybrid vehicles, U.S. Pat. No. 5,172,784 discloses the use of an external combustion, free piston engine which is capable of burning variety of fuels.
The paper entitled "Hybrid/Electric: Vehicle Design Options and Evaluations" by A. F. Burke, SAE International Congress and Exposition, Feb. 1992, describes a large variety of hybrid electric vehicle configurations, but does not provide any details regarding their respective control systems.
None of the power trains described in these patent references deal with the use of a flywheel for energy storage and surge power, the use of a gas turbine as the heat engine, or the interrelated dynamic control of such systems.